HONOLULU (AP) - Hawaii Gov. Neil Abercrombie signed a bill Wednesday legalizing gay marriage in the state that kicked off a national discussion of the issue more than two decades ago.

Now, the island chain is positioning itself for a bump in tourism as people take advantage of the new law and the state provides another example of how differently marriage is viewed in the nation.

"In Hawaii, we believe in fairness, justice and human equality," Abercrombie said Tuesday after the state Senate passed the gay marriage bill. "Today, we celebrate our diversity defining us rather than dividing us."

Hawaii's gay marriage debate began in 1990 when two women applied for a marriage license, leading to a court battle and a 1993 Hawaii Supreme Court decision that said their rights to equal protection were violated by not letting them marry.

That helped lead Congress to pass the federal Defense of Marriage Act in 1996, part of which was struck down earlier this year by the U.S. Supreme Court.

The decision led Abercrombie to call a special session that produced Hawaii's gay marriage law.

Abercrombie signed the measure at an invitation-only ceremony at the Hawaii Convention Center, near the tourism hub of Waikiki.

The law allows gay couples living in Hawaii and tourists to marry in the state starting Dec. 2. Another 14 states and the District of Columbia already allow same-sex marriage. A bill is awaiting the governor's signature in Illinois.

President Barack Obama praised passage of the Hawaii bill, saying the affirmation of freedom and equality makes the country stronger.

Senators passed the measure 19-4 with two lawmakers excused.

Rep. Bob McDermott, a House lawmaker who filed a lawsuit to derail the special session, promised a new challenge after Abercrombie signed the bill. A judge said he would take up the case only after the law was fully passed.

An estimate from a University of Hawaii researcher says gay marriage will boost tourism by $217 million over the next three years, as Hawaii becomes a destination for couples in other states, boosting ceremonies, receptions and honeymoons in the islands.

The bump is expected to level out as early trips decrease and possibly more states legalize gay marriage.

"We do know from lots of other states, if they don't live in a state with marriage equality, they will travel," said Lee Badgett, an economics professor at University of Massachusetts-Amherst and senior scholar at UCLA's Williams Institute, a think-tank that conducts law and public policy research on sexual orientation and gender identity issues. "It's a reasonable expectation people will want to go to Hawaii. It's a big wedding destination spot."

But Badgett said Hawaii has competition from other states where gays can marry: "Some of them are making a play for same-sex couples very deliberately. ... That's totally new spending, and that's great for the economy."